Bearing structure for continuous casting machine

ABSTRACT

A bearing structure for a curved continuous casting machine includes a monolithic and integrated structure, made of metal sheet, substantially closed and self-bearing, having at the upper part a seating or base suitable for the assembly of an ingot mold and accommodating along the casting curve both the rolls for containing and guiding the cast product, and also at least part of a secondary cooling system.

FIELD OF THE INVENTION

The present invention concerns a bearing structure for a continuouscasting machine.

More particularly, the invention concerns a monolithic and integratedbearing structure, particularly suitable to be used for the installationof a compact curved continuous casting machine, in particular for thecontinuous casting of billets and blooms, for example but not only, forcommercial steels, but also for quality steels.

The monolithic and integrated bearing structure according to the presentinvention allows to install a single line and/or multi-line continuouscasting machine, considerably reducing and simplifying the assemblyoperations in loco, drastically reducing times required for start-up,and also the costs of initial investment.

Furthermore, the bearing structure according to the invention ensures aneasier access for operators to the casting line, for example formaintenance operations, and guarantees greater operating safety for saidoperators.

BACKGROUND OF THE INVENTION

The general structure of a continuous casting machine for billets orblooms is known, comprising in its essential elements an ingot mold witha square or rectangular section, the foot rolls and a curved removal andguide line, associated with a secondary cooling system.

Downstream of the removal and guide line there is normally astraightening device, the function of which is to dispose the castbillet or bloom flat, in order to accompany it towards the equipmentlocated downstream, for example shearing means, removal and parkingmeans for the dummy bar, the accumulation and heating systems and/or therolling train.

Examples of said curved continuous casting machines are shown forexample in JP 59110453 and CH 597944.

It is known that the installation of a curved continuous casting machinenormally requires expensive civil engineering works, such asexcavations, foundations for machines, concrete casts, bearing columns,reinforced concrete beams and more, all of which makes the installationtimes extremely long, and initial investment costs extremely high.

Moreover, known solutions require a long time, and a specialized workforce, to make the connections to the user machines on site, for exampleto connect the pipes to feed water, air, piping, electric connectionsand other.

Furthermore, to make said connections requires a precise and expensiveinitial planning step, so that all the connection systems and theauxiliary and accessory equipment are positioned in places which on theone hand do not interfere with the daily operations of the castingmachine and are adequately protected, and on the other hand are easilyand quickly accessible and maintainable in the event of problems andbreak-downs.

Another problem in known solutions is the huge need for space in theshed for the installation of the usual continuous casting machines,which moreover are normally located on different planes. Another problemis the expense of the transport in loco of the components of thecontinuous casting machine.

Still another problem is the difficult access for operators to theindividual segments of the line, for example to make inspections,maintenance, replacement of components, or to solve problems ofblockages or other type.

Purpose of the present invention is to achieve plants for rollingbillets or blooms of the compact type, with pre-assembled components,also of the structural type, already complete with pre-tested plantengineering, with shorter assembly time, also suitable to be installedin limited spaces.

In the light of the above, purpose of the present invention is thereforeto solve these problems, proposing a solution able to drastically reducethe works of civil engineering needed for the installation of acontinuous casting machine in a plant, the design and need for labor toperform the connections to the user machines, the volumes of transportand loading/unloading the components, and all the other works requiredto install the continuous casting machine.

The Applicant has devised, tested and embodied the present invention toobtain this purpose, and other benefits and advantages as shownhereafter, including for example greater safety for the workers.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independentclaim, while the dependent claims describe other characteristics of theinvention or variants to the main inventive idea.

In accordance with the present invention, the purpose set forth above isobtained by using a monolithic and integrated structure, made of metalsheet, substantially closed and self-supporting, which has a seatingsuitable for the assembly of an ingot mold and which accommodates boththe containing and guiding rolls disposed along the curvilinear path ofthe cast product, and also the secondary cooling system.

The bearing structure is advantageously made from workings on machinetools which allow to obtain limited tolerances in the construction ofthe components.

With the bearing structure according to the invention, during theassembly step of the casting line, it is possible to obtain immediatelya perfect alignment of the containing and guiding rolls of the castproduct, so that it is no longer necessary to perform all the operationsthat normally, in conventional assembly operations, are actuated toeffect said alignment subsequent to installation.

Moreover, the monolithic bearing structure according to the inventiondoes not require expensive works of civil engineering, such as thetraditional foundations for the machines, but simply a plane supportingsurface on which it can be anchored.

In an advantageous embodiment of the invention, the whole bearingstructure is anchored to the ground by means of at least a metal plate,which functions as a base, incorporated into the floor and made solidtherewith, for example, but not necessarily, by means of threaded barsor tie rods. This allows to reduce the installation times and initialinvestment costs.

In a preferential embodiment of the invention, at least the upperportion of the casting curve is easily accessible by means of a seriesof opening covers that allow selective opening to adjacent individualsegments of the casting line.

The covers have a box-like structure, substantially U-shaped, conformedso as to be disposed, in the closed position, as close as possible tothe casting line, almost so as to surround it; in the zones where it isconnected to the containing structure of the cast product, leakages ofwater are prevented by using, for example, suitable labyrinth seals.

In this way, we obtain a great overall saving of space around thecontinuous casting machine, so that the size of the compartmentcontaining the billet/bloom along the casting curve is reduced to aminimum. Moreover, even in the open position the covers do not need bigspaces around the casting machine in order to be moved.

In a preferential embodiment of the invention, the covers can be openedin an upward direction, so as to allow operators access to the line fromboth sides of the line.

According to a variant, the covers can be opened in a lateral direction.In this case, the opening/closing of the covers is performed insequence, to prevent the ends of two adjacent covers from overlapping.

The presence of opening covers allows to considerably facilitate, forthe staff, all the interventions of checking and ordinary (daily)maintenance, checking the insertion of the dummy bar when casting isstarted, the management of possible problems, such as leakage of liquidsteel due to the breakage of the skin, and other: all this promotesgreater rapidity in operations and greater safety for the workers.

In one embodiment of the invention, inside the covers at least the uppercontaining and guiding rolls for the billet/bloom are assembled.

According to a variant, inside the box-like containing structure of thecast product support means, alignment means and/or command means of thelower rolls are assembled.

According to another variant, the spray nozzles of the secondary coolingsystem are assembled inside the covers.

Thanks to this pre-assembly of functional elements of the casting line,when the covers are closed, all the relative equipment assembled insideis already in the position of use, therefore without requiring furthersteps of adjustment or tuning, both in terms of geometry and alignment,all of which guarantees greater efficiency of the process.

The covers are advantageously cooled by suitable means, for examplesprays, or by means of a water jacket structure with an independentcircuit, and they are driven to open/close for example by means ofhydraulic actuators or jacks.

As mentioned above, the monolithic casting structure advantageouslyprovides on the outside all the necessary drive and command elements,such as for example the rapid attachments for water and electricity, thesystem for lubricating the bearings, the piping, etc. These elements areeasily and quickly interfaced with the appropriate service lines of theplant (electricity, water plant, oil plant, air plant, etc.).

In a preferential embodiment, in the upper part of the casting line, itis provided to suck in the water vapors generated by the process, with asuitable aspirator; the suction is facilitated thanks to the limitedsize of the casting chamber, and the fact that the closed monolithicstructure produces a “chimney effect”.

The plant according to the present invention allows to considerablysimplify the works of civil engineering for installation, since it doesnot require complex foundations and does not require the traditionalbearing structure made of reinforced concrete and network of girders tosupport the various planes of the structure.

The bearing structure according to the invention has limited weight andsize and, since it is made largely of modular elements, it is easy totransport.

The presence inside and/or outside the monolithic structure of all thedrive and command devices allows rapid installation and rapid start-upof the plant.

Thanks to all these details indicated above, the continuous castingmachine thus made allows to use adjacent casting lines in parallel, ifit is desired to increase productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will becomeapparent from the following description of a preferential form ofembodiment, given as a non-restrictive example with reference to theattached drawings wherein:

FIG. 1 is a perspective view of a bearing structure for a continuouscasting machine according to the present invention;

FIGS. 2 and 3 show respectively a lateral view and a view from the rearof the bearing structure in FIG. 1;

FIG. 4 is a perspective view of the bearing structure in FIG. 1 in whichthe covers with lateral opening can be seen;

FIG. 4 a shows an enlarged detail of FIG. 4;

FIGS. 5 and 6 show, respectively with a perspective view and a lateralview, the bearing structure in FIG. 4 in which the covers open upwards;

FIG. 7 shows a continuous casting machine that uses a bearing structureaccording to the present invention inserted upstream of a partly shownsegment of line; and

FIG. 8 is a perspective view of another form of embodiment of thebearing structure according to the invention.

DETAILED DESCRIPTION OF SOME PREFERENTIAL FORMS OF EMBODIMENT

With reference to the attached drawings, and particularly FIG. 7, abearing structure 10 for a curved continuous casting machine accordingto the present invention is disposed upstream of a straightening unit11, a device 12 to insert, remove and park a dummy bar 13, and shears14.

Downstream of the shears 14, and not shown here, there may be a heatingfurnace present and a rolling train directly connected with the productarriving from the casting machine in the case of an application to aproduction plant of the endless type.

The bearing structure 10 according to the invention in this case isdisposed in cooperation with a bridge 15, defining the casting plane 17,having a width advantageously equal to that of a bay of the shed of theplant where the casting machine is installed.

With this configuration it is possible to create a passage space at theside of the casting line, which allows the workers and the equipment tohave access upstream and downstream of the plant, thus allowing agreater integration of the areas.

Under the casting plane 17 an intermediate plane 16 is provided, whereall the auxiliary services are accommodated, such as for example theoil-dynamic units, the electric panels, the regulation valves, thepiping, the collectors.

The casting plane 17 is advantageously not bulky and can have a veryrational disposition of the auxiliary devices.

The bearing structure 10 in this case is anchored to the ground by meansof a metal plate 21, functioning as a base, incorporated into the floor.A column element 20 is attached on the metal plate 21, defining astructure which in this case is quadrangular, consisting in this case offour metal beams 22, for example H beams or other type (FIGS. 1 and 2).

At the top end of the column element 20, inside a containing frame 18, aflange 23 is assembled which defines a seating or base, in which aningot mold 24 is housed and assembled.

The flange is advantageously of the inter-changeable type so as to allowthe assembly of an ingot mold 24 different in the event of a change informat of the billet/bloom 26.

From the column element 20 a series of lateral and bottom panels 25,made of metal sheet, attached one to the other in sequence, branch offtowards the bottom and towards the base; they define a box-likestructure which houses and defines the curved removal and guide line ofthe billet/bloom 26.

The lateral and bottom panels 25 define a seating for the housing andassembly at least of the lower rolls and the nozzles of the secondarycooling system.

On the lateral panels 25 a series of opening covers 28 are hinged, bymeans of respective assembly plates 27, substantially U-shaped, whichopen laterally in the case shown in FIG. 4, whereas in the case shown inFIG. 6 they open upwards with respect to the casting line.

The covers 28 may be driven to open by means of respective hydraulic orpneumatic jacks 36, which allows selective access to respective segmentsof the line for a worker 29, also thanks to the presence of a system ofstairs 30 that develops adjacent to the panels 25, in order to carry outinspection or maintenance operations, and in the event of incidents suchas blockages or break-outs.

The U-shaped surrounding box-like structure of the covers 28 allows toreduce to a minimum indispensable the size of the casting chamberdownstream of the ingot mold 24, thus giving a better thermodynamiccontrol of the conditions of progressive solidification of thebillet-bloom 26, and an easier control to prevent leakages of thecooling water.

When the covers 28 open from above as in the case shown in FIG. 4, wherethe covers 28 can be seen progressively closing from the bottom of thecasting line, the opening and closing of the covers 28 is performedsequentially so that there is no overlapping of the adjacent ends.

According to the variant shown in FIG. 8, the first segment of thecasting line downstream of the ingot mold 24 comprises a substantiallyclosed chamber 37, which may or may not comprise the column element 20,and which allows easy access to the operators. The closed chamber 37allows to control the cooling system better and more easily duringcasting and is less subject to reverberation by the billet/bloom 26since the walls are more distant therefrom compared with the solutionwith covers 28. The subsequent part of the casting curve, on thecontrary, provides the opening covers 28, as in the solutions previouslydescribed.

Inside the covers 28, as shown in detail in FIG. 4 a, both the upperrolls 32 to contain and guide the billet/bloom 26 are advantageouslyassembled, and also the nozzles 42 of the secondary cooling system.Thanks to this system of pre-assembly, at the moment the covers 28 areinstalled, and when they close, the curved removal and guide line of thebillet/bloom 26 is already completely configured, without needingalignments and further adjustments.

In a first embodiment of the invention, only one of the roll units, theupper or the lower, is motorized, while the other is idle.

According to a variant, both the roll units are motorized. According toanother variant, both the roll units are idle.

In the preferential embodiment shown in FIGS. 2 and 8, the base plate 33of the column element 20 has rapid attachment means 34, accessible fromoutside, for connection to the service sources, for example water, air,electricity, possible oil plant, piping and other.

The rapid attachment means 34 can be used to activate the necessaryconnections in an extremely rapid and simple manner, without requiringspecialized labor and without needing complex positioning which canoblige the workers to perform complex and dangerous operations. Therapid attachment means 34 is connected, inside the column element 20,with pipes and cables, indicated in their entirety by the referencenumber 35, which serve to deliver water, electricity and other to thedelivery points distributed inside the bearing structure 10.

The water used for the secondary cooling is conveyed and channeled,together with the scale, along a slide advantageously made with thebottom panels 25 of the casting curve, and subsequently discharged fromthe lower end of the curve into the so-called “flushing”, that is, thewater treatment plant of the works.

According to a variant, the casting curve is made without the bottompanels and the lateral panels extend to the ground so as to constitutetwo continuous lateral walls. In this case, the cooling water is notconveyed along the curve, but falls directly to floor level, where it iscollected in the flushing.

Modifications and variants may be made to the present invention, all ofwhich shall come within the field of protection defined by the attachedclaims.

1. A bearing structure for a curved continuous casting machine,comprising a monolithic and integrated structure, made of metal sheet,substantially closed and self-bearing, having at the upper part aseating or base suitable for the assembly of an ingot mold andaccommodating along the casting curve both the rolls for containing andguiding the cast product, and also at least part of the secondarycooling system.
 2. The bearing structure as in claim 1, comprising ametal plate functioning as a base and able to be incorporated into thefloor.
 3. The bearing structure as in claim 1, comprising a plurality oflateral and bottom panels defining a body supporting at least the lowerrolls containing and guiding the casting line.
 4. The bearing structureas in claim 1, comprising, at least in correspondence with the lowerportion of the casting curve, it has a plurality of opening covers ableto allow access to the relative segments of the casting curve.
 5. BThebearing structure as in claim 4, wherein said opening covers have asubstantially U-shaped structure surrounding the relative segment of thecasting curve.
 6. The bearing structure as in claim 4, wherein saidcovers open in an upward direction with respect to the casting line. 7.The bearing structure as in claim 4, wherein said covers open in alateral direction with respect to the casting line.
 8. The bearingstructure as in claim 4, wherein inside said covers at least the upperrolls for containing and guiding the casting line are assembled.
 9. Thebearing structure as in claim 4, characterized wherein inside saidcovers at least part of the nozzles of the secondary cooling system ofthe casting line are assembled.
 10. The bearing structure as in claim 1,comprising rapid attachment means for connection to a source of electricand/or water feed.
 11. The bearing structure as in claim 1, wherein thebearing structure comprises inside itself rapid connection means andinterconnection means to feed lubrication systems.
 12. The bearingstructure as in claim 1, comprising a substantially closed chamberdisposed immediately downstream from the exit of the ingot-mold andcovering at least the upper segment of the casting curve.
 13. Thebearing structure as in claim 1, able to be installed in a shed of aproduction plant, wherein the bearing structure is located incooperation with a bridge, defining the casting plane, having a widthsubstantially equal to that of a bay of said shed.
 14. The bearingstructure as in claim 13, wherein below the casting plane the bridgecomprises at least an intermediate plane for accommodating at least partof the services auxiliary to casting.